Currently I have the following Dockerfile:
FROM debian:10 as builder
RUN sleep 10
COPY input input
# worlds most trivial build pipeline
RUN cat input > artifact
FROM debian:10
COPY --from=builder artifact artifact
RUN cat artifact
COPY input2 input2
And I have docker-compose file like the following:
%YAML 1.1
---
version: '3.7'
services:
sdn-controller:
build:
context: .
cache_from:
- hansbogert/test1:latest
args:
- BUILDKIT_INLINE_CACHE=1
image: hansbogert/test1:latest
And two empty files:
$ touch input input2
If I do an initial build with buildkit, and push them to the registry:
export DOCKER_BUILDKIT=1
docker-compose build
docker-compose push
Keeping the cache-from in mind in the compose file:
case 1) I expect that when I have no local cache, i.e.,
docker rmi hansbogert/test1 ; docker image prune -f; docker builder prune -af
that a new build would be completely cached, (which it is):
docker-compose build
[trunc'd, but all cached]
case 2) I expect that if I edit the input2 file, that only the latest stage in the docker file, starting from the COPY-ing of input2 needs to be redone, which it does:
$ echo 1 > input2
$ docker rmi hansbogert/test1 ; docker image prune -f; docker builder prune -af
$ docker-compose build
[trunc'd]
=> CACHED [stage-1 3/4] RUN cat artifact 0.7s
=> => pulling sha256:f33c84f9d3c6505acdda2a6d1c7238c853e07f3723e4a5d4c9eb65a163710ffd 0.3s
=> => pulling sha256:0b00a0a96175fa32a06c3741ac1fb655aafc2ed1584eebfd2e213561998f7bea 0.4s
=> [stage-1 4/4] COPY input2 input2 0.0s
=> exporting to image
...
case 3) When I edit the input file, I expect the first stage to be cached up till the COPY input input line, alas, that's what does not happen, signalled by the uncache RUN sleep 10 line:
$ echo 1 > input
$ docker rmi hansbogert/test1 ; docker image prune -f; docker builder prune -af
$ docker-compose build
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 254B 0.0s
=> [internal] load .dockerignore 0.1s
=> => transferring context: 2B 0.0s
=> [internal] load metadata for docker.io/library/debian:10 0.0s
=> importing cache manifest from hansbogert/test1:latest 1.3s
=> [builder 1/4] FROM docker.io/library/debian:10 0.1s
=> [internal] load build context 0.0s
=> => transferring context: 71B 0.0s
=> [builder 2/4] RUN sleep 10 10.5s
=> [builder 3/4] COPY input input 0.1s
=> [builder 4/4] RUN echo input > artifact 0.6s
=> CACHED [stage-1 2/4] COPY --from=builder artifact artifact 0.0s
[trunc'd, but note that this stage is cached as much as possible! ]
Main question: Is there a way to get caching for stages other than the stage in the final image?
There seems to be a relevant issue on github
However, in its conclusion it does not seem to address my above problem.
